ext4: check for shutdown and r/o file system in ext4_write_inode()

If the file system has been shut down or is read-only, then
ext4_write_inode() needs to bail out early.

Also use jbd2_complete_transaction() instead of ext4_force_commit() so
we only force a commit if it is needed.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

fs/ext4/inode.c

@@ -5400,9 +5400,13 @@ int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
 {
 	int err;
 
-	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
+	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC) ||
+	    sb_rdonly(inode->i_sb))
 		return 0;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	if (EXT4_SB(inode->i_sb)->s_journal) {
 		if (ext4_journal_current_handle()) {
 			jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
@@ -5418,7 +5422,8 @@ int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
 		if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync)
 			return 0;
 
-		err = ext4_force_commit(inode->i_sb);
+		err = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
+						EXT4_I(inode)->i_sync_tid);
 	} else {
 		struct ext4_iloc iloc;